There Are Way Too Many Nuclear Weapons

Nuclear war is a scary proposition. Nuclear winter would be even deadlier.

A study published last week calculated the devastating impact a major nuclear conflict could have on the world’s food production. Authors Joshua Pearce and David Denkenberger developed a step-by-step model of nuclear winter and estimated the climate impact. In the aftermath of nuclear war, smoke would rise up and block the necessary sunlight for vital crops and food supplies to grow.

“Even in a country that has a lot of food like the United States, there is still potential for significant starvation,” Denkenberger says.

The research concluded that 100 nuclear weapons is the “pragmatic” number for nuclear deterrence. Keeping more than that, the authors argue, is irrationally expensive and dangerous. The United States has approximately 6,800 nuclear warheads as of 2017.

“The immediate impact of the blast and the radiation and the fires directly impacting cities is more dramatic,” Denkenberger says. “But it turns out the slow process of the smoke in the atmosphere is likely to kill many more people than the direct use of nuclear weapons.”

Nuclear winter would follow the initial destruction, a planetary cooling that would produce winter-like conditions all year round. Denkenberger has spent years studying the phenomenon as the director and co-founder of the Alliance to Feed the Earth in Disasters (ALLFED). Nuclear winter’s effect on food production would be catastrophic. Even a less extreme cooling, known as nuclear autumn, would still significantly alter food production.

“[According to] this crop modeling, if temperatures globally fell, say, two degrees fahrenheit, food production would decrease by 10 percent. That’s a big deal,” Denkenberger says. “Food prices would rise dramatically in that case.”

But there are optimistic points. The United Nations also banned nuclear weapons last year in an attempt to stigmatize—if not completely dissuade—countries from holding or trying to develop them. Both the United States and Russia—by far the world’s biggest nuclear nations—have significantly reduced their stockpiles since the 1980s since the initial awareness of nuclear winter came to light.

“The build-up between the U.S. and the Soviet Union was an arms race,” Denkenberger says. “It wasn’t motivated by any kind of pragmatic logic.”

The question is whether pragmatic logic will prevail.